Prepaid Cell Phones

Who can tell me about prepaid cell phones? I have been trying to figure them out, and I can't find a simple description of what is offered. For example AT&T seems to have a "no contract" option that is like $45/month. But do they have just a flat prepaid option like a tracfone?
Basically, I'm looking for the cheapest prepaid cell phone with bluetooth I can get my hands on that will work in Townsend, WI. According to Walmart.com, Tracfone will not work there.
I'm trying to set up a temperature/power/water monitoring system at my cabin and I need a bluetooth capable cell phone to get it done. US Cellular wants $40/month to activate an additional line, which was insane to me.
Sorry for the rambling and thanks for any help you can provide. I'm been looking at this stuff too long and I'm going nuts!

You can probably pick up a cheap tracfone for about $10. I do not remember what the 30 minute card cost. Take it up to the cabin and make a few calls and see what happens.

Either that or find a buddy with a tracfone and buy him a 30 minute card and take him along to try it out.

From the way I understand it, Tracfone operates on whatever signal is available.

You might have to go out and walk around a little bit to see if you can pick up a signal. I had to do that a few years ago at a friend's cabin. Now it does not seem to be a problem when we go there.

I have used tracfones for at least 20 years, now I have 2, one to call the kids on and one to receive calls from everybody else. If you decide to go with a better phone, make sure you get one either with the triple minutes or the triple time, minutes and something else. I think with mine 1200 minutes for a years time is about $90. I always get the 450 minutes for 90 days because I have plenty of time I have not used on both phones. Hope this helps.